Tuesday, November 13, 2012

TOTAL SOLAR ECLIPSE: 14 NOVEMBER 2012

"A Total Eclipse of the Sun will occur over Northern Australia early in the morning of 14 November 2012. This spectacular phenomenon is probably the most awe inspiring event in the natural world."

What is a Total Solar Eclipse?

"An eclipse of the Sun occurs when the moon passes between the earth and the Sun. The Sun is much larger than the moon, it is also much further away, such that the two bodies appear to be about the same size in the sky. During a total solar eclipse, the moon moves in front of the Sun and completely covers it. This casts a shadow on the Earth’s surface. As the moon orbits the Earth and the Earth rotates, the shadow moves across the Earths surface in a narrow path generally from west to east. To see a Total Solar Eclipse you must be in the shadow’s path. If you are outside the shadow’s path at the time of the eclipse, the moon will not completely cover the Sun and you will only see partial eclipse.

During the partial phase of the eclipse, the moon gradually covers the Sun. This takes about an hour. As the total part of the eclipse approaches, the sky becomes darker and an ominous black shadow approaches from the west. The Sun is reduced to a thin crescent. The temperature can drop significantly. In the final few seconds before totality, the last brilliant parts of the Sun’s surface shine through valleys on the moon in a shimmering display called Baily’s Beads.

Finally the beads are reduced to a single point and the Sun looks like a dazzling diamond ring. As the last bright point winks out, the Sun’s pink upper surface called the chromosphere can be seen around the edge of the moon and often prominences, pink loops of plasma extending above the chromosphere, are visible. During totality, the moon appears as a black hole in the sky surrounded by the pearly white Corona, the Sun’s outer atmosphere composed of ionised gas which curves out from the Sun, usually in a pattern formed by the Sun’s magnetic field. The whole sky is dark in a surreal twilight with a glowing light around the horizon with a sunset tinge which is caused by the scattering of different wavelengths of light in the atmosphere. At the end of totality the sequence is reversed, with prominences, chromosphere, diamond ring and Baily’s Beads again being visible. The moon then gradually uncovers the Sun, taking about an hour until the partial phase is over."